Self-assembling peptides for successful hemostasis in advanced gastric cancer

Endoscopic hemostasis of bleeding from advanced gastric cancer is difficult because of the multiple sources and fragile tissues. Palliative radiotherapy, although effective, takes time to be effective.^{1, 2}

The endoscopic application of a self-assembling peptide (SAP; PuraStat; 3-D Matrix, Tokyo, Japan) has been reported as a bridge to radiotherapy.³ However, maintaining the visual field through air inflation is difficult because of blood pooling and wall stiffness.

Gel immersion endoscopy allows visualization under conditions of poor visibility.^{4, 5} However, it is unknown whether SAP coating is possible under gel immersion conditions.

Here, we demonstrate the application of SAP under gel immersion by a phantom experiment and report successful hemostasis of tumor bleeding by SAP application under gel immersion called the “gel under gel” technique (Video S1).

We modeled a hemorrhage by injecting simulated blood from a tube in an acrylic aquarium (Fig. 1a,b). We used an irrigation valve (BioShield irrigator; STERIS, Mentor, OH, USA) to simultaneously inject a transparent gel (Viscoclear; Otsuka Pharmaceutical Factory, Tokushima, Japan) and applied the SAP to the hemorrhage site using a dedicated catheter (Fig. 1c). By extruding the SAP with an indigo carmine solution instead of air, the end of the SAP use could be determined without bubbling. The gels did not mix, and the gel-forming SAP remained at the bleeding point after the surrounding gel was removed.

A 53-year-old man with advanced gastric cancer presented with severe anemia. Esophagogastroduodenoscopy revealed multiple bleeding points (Fig. 2a). The bleeding points were clearly identified by transparent gel injection. Hemostasis was achieved by applying the SAP using a catheter during gel immersion (Fig. 2b). The gel-forming SAP remained attached to the tumor surface, and complete hemostasis was achieved (Fig. 2c).

Self-assembling peptide application under gel immersion may be useful for achieving hemostasis in bleeding tumors by maintaining a clear visual field.

Authors declare no conflict of interest for this article.